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Su TF, Hamilton JD, Guo Y, Potas JR, Shivdasani MN, Moalem-Taylor G, Fridman GY, Aplin FP. Peripheral direct current reduces naturally evoked nociceptive activity at the spinal cord in rodent models of pain. J Neural Eng 2024; 21:026044. [PMID: 38579742 DOI: 10.1088/1741-2552/ad3b6c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 04/05/2024] [Indexed: 04/07/2024]
Abstract
Objective.Electrical neuromodulation is an established non-pharmacological treatment for chronic pain. However, existing devices using pulsatile stimulation typically inhibit pain pathways indirectly and are not suitable for all types of chronic pain. Direct current (DC) stimulation is a recently developed technology which affects small-diameter fibres more strongly than pulsatile stimulation. Since nociceptors are predominantly small-diameter Aδand C fibres, we investigated if this property could be applied to preferentially reduce nociceptive signalling.Approach.We applied a DC waveform to the sciatic nerve in rats of both sexes and recorded multi-unit spinal activity evoked at the hindpaw using various natural stimuli corresponding to different sensory modalities rather than broad-spectrum electrical stimulus. To determine if DC neuromodulation is effective across different types of chronic pain, tests were performed in models of neuropathic and inflammatory pain.Main results.We found that in both pain models tested, DC application reduced responses evoked by noxious stimuli, as well as tactile-evoked responses which we suggest may be involved in allodynia. Different spinal activity of different modalities were reduced in naïve animals compared to the pain models, indicating that physiological changes such as those mediated by disease states could play a larger role than previously thought in determining neuromodulation outcomes.Significance.Our findings support the continued development of DC neuromodulation as a method for reduction of nociceptive signalling, and suggests that it may be effective at treating a broader range of aberrant pain conditions than existing devices.
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Affiliation(s)
- Tom F Su
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Jack D Hamilton
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Yiru Guo
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Jason R Potas
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
- Eccles Institute, John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Mohit N Shivdasani
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Gila Moalem-Taylor
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Gene Y Fridman
- Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States of America
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States of America
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States of America
| | - Felix P Aplin
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
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2
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Rugnath R, Orzechowicz C, Newell C, Carullo V, Rugnath A. A Literature Review: The Mechanisms and Treatment of Neuropathic Pain-A Brief Discussion. Biomedicines 2024; 12:204. [PMID: 38255308 PMCID: PMC10812949 DOI: 10.3390/biomedicines12010204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 01/24/2024] Open
Abstract
Classically, neuropathic pain is described as a pain caused by a lesion or disease of the somatosensory system. However, one must note that the presence of somatosensory pathology alone does not guarantee a progression to neuropathic pain. This is due, in part, to the fact that neuropathic pain is a notoriously complex disease process, involving sensitization of both the central and peripheral nervous systems. Its causes are also numerous and varied, including trauma, the compression of a nerve, autoimmune disorders, diabetes, and infections. Due to the various manifestations, causes, and symptoms of neuropathic pain, the treatment of this disease process has proved challenging for generations of physicians. This section aims to elaborate on newly proposed mechanisms for pharmacological and targeted therapies, such as neurostimulation, which aim to reduce the negative somatosensory effects of neuropathic pain.
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Affiliation(s)
| | | | | | | | - Anesh Rugnath
- Department and Anesthesiology, University of Mississippi Medical Center, Jackson, MS 39216, USA; (R.R.)
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3
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Ueda H, Neyama H. Fibromyalgia Animal Models Using Intermittent Cold and Psychological Stress. Biomedicines 2023; 12:56. [PMID: 38255163 PMCID: PMC10813244 DOI: 10.3390/biomedicines12010056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 01/24/2024] Open
Abstract
Fibromyalgia (FM) is a chronic pain condition characterized by widespread musculoskeletal pain and other frequent symptoms such as fatigue, sleep disturbance, cognitive impairment, and mood disorder. Based on the view that intermittent stress would be the most probable etiology for FM, intermittent cold- and intermittent psychological stress-induced generalized pain (ICGP and IPGP) models in mice have been developed and validated as FM-like pain models in terms of the patho-physiological and pharmacotherapeutic features that are shared with clinical versions. Both models show long-lasting and generalized pain and female-predominant sex differences after gonadectomy. Like many other neuropathic pain models, ICGP and IPGP were abolished in lysophosphatidic acid receptor 1 (LPAR1) knock-out mice or by LPAR1 antagonist treatments, although deciding the clinical importance of this mechanism depends on waiting for the development of a clinically available LPAR1 antagonist. On the other hand, the nonsteroidal anti-inflammatory drug diclofenac with morphine did not suppress hyperalgesia in these models, and this is consistent with the clinical findings. Pharmacological studies suggest that the lack of morphine analgesia is associated with opioid tolerance upon the stress-induced release of endorphins and subsequent counterbalance through anti-opioid NMDA receptor mechanisms. Regarding pharmacotherapy, hyperalgesia in both models was suppressed by pregabalin and duloxetine, which have been approved for FM treatment in clinic. Notably, repeated treatments with mirtazapine, an α2 adrenergic receptor antagonist-type antidepressant, and donepezil, a drug for treating Alzheimer's disease, showed potent therapeutic actions in these models. However, the pharmacotherapeutic treatment should be carried out 3 months after stress, which is stated in the FM guideline, and many preclinical studies, such as those analyzing molecular and cellular mechanisms, as well as additional evidence using different animal models, are required. Thus, the ICGP and IPGP models have the potential to help discover and characterize new therapeutic medicines that might be used for the radical treatment of FM, although there are several limitations to be overcome.
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Affiliation(s)
- Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan;
- Department and Graduate Institute of Pharmacology, National Defense Medical Center, Taipei 114201, Taiwan
| | - Hiroyuki Neyama
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8521, Japan;
- Multiomics Platform, Center for Cancer Immunotherapy and Immunobiology, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
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4
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Kamada H, Emura K, Yamamoto R, Kawahara K, Uto S, Minami T, Ito S, Matsumoto KI, Okuda-Ashitaka E. Hypersensitivity of myelinated A-fibers via toll-like receptor 5 promotes mechanical allodynia in tenascin-X-deficient mice associated with Ehlers-Danlos syndrome. Sci Rep 2023; 13:18490. [PMID: 37898719 PMCID: PMC10613304 DOI: 10.1038/s41598-023-45638-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 10/21/2023] [Indexed: 10/30/2023] Open
Abstract
Deficiency of an extracellular matrix glycoprotein tenascin-X (TNX) leads to a human heritable disorder Ehlers-Danlos syndrome, and TNX-deficient patients complain of chronic joint pain, myalgia, paresthesia, and axonal polyneuropathy. We previously reported that TNX-deficient (Tnxb-/-) mice exhibit mechanical allodynia and hypersensitivity to myelinated A-fibers. Here, we investigated the pain response of Tnxb-/- mice using pharmacological silencing of A-fibers with co-injection of N-(2,6-Dimethylphenylcarbamoylmethyl) triethylammonium bromide (QX-314), a membrane-impermeable lidocaine analog, plus flagellin, a toll-like receptor 5 (TLR5) ligand. Intraplantar co-injection of QX-314 and flagellin significantly increased the paw withdrawal threshold to transcutaneous sine wave stimuli at frequencies of 250 Hz (Aδ fiber responses) and 2000 Hz (Aβ fiber responses), but not 5 Hz (C fiber responses) in wild-type mice. The QX-314 plus flagellin-induced silencing of Aδ- and Aβ-fibers was also observed in Tnxb-/- mice. Co-injection of QX-314 and flagellin significantly inhibited the mechanical allodynia and neuronal activation of the spinal dorsal horn in Tnxb-/- mice. Interestingly, QX-314 alone inhibited the mechanical allodynia in Tnxb-/- mice, and it increased the paw withdrawal threshold to stimuli at frequencies of 250 Hz and 2000 Hz in Tnxb-/- mice, but not in wild-type mice. The inhibition of mechanical allodynia induced by QX-314 alone was blocked by intraplantar injection of a TLR5 antagonist TH1020 in Tnxb-/- mice. These results suggest that mechanical allodynia due to TNX deficiency is caused by the hypersensitivity of Aδ- and Aβ-fibers, and it is induced by constitutive activation of TLR5.
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Affiliation(s)
- Hiroki Kamada
- Department of Biomedical Engineering, Osaka Institute of Technology, Osaka, 535-8585, Japan
| | - Kousuke Emura
- Department of Biomedical Engineering, Osaka Institute of Technology, Osaka, 535-8585, Japan
| | - Rikuto Yamamoto
- Department of Biomedical Engineering, Osaka Institute of Technology, Osaka, 535-8585, Japan
| | - Koichi Kawahara
- Department of Biomedical Engineering, Osaka Institute of Technology, Osaka, 535-8585, Japan
| | - Sadahito Uto
- Department of Biomedical Engineering, Osaka Institute of Technology, Osaka, 535-8585, Japan
| | - Toshiaki Minami
- Department of Anesthesiology, Osaka Medical and Pharmaceutical University, Takatsuki, 569-8686, Japan
| | - Seiji Ito
- Department of Anesthesiology, Osaka Medical and Pharmaceutical University, Takatsuki, 569-8686, Japan
| | - Ken-Ichi Matsumoto
- Department of Biosignaling and Radioisotope Experiment, Interdisciplinary Center for Science Research, Head Office for Research and Academic Information, Shimane University, Izumo, 693-8501, Japan
| | - Emiko Okuda-Ashitaka
- Department of Biomedical Engineering, Osaka Institute of Technology, Osaka, 535-8585, Japan.
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5
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Ciotu CI, Kistner K, Kaindl U, Millesi F, Weiss T, Radtke C, Kremer A, Schmidt K, Fischer MJM. Schwann cell stimulation induces functional and structural changes in peripheral nerves. Glia 2023; 71:945-956. [PMID: 36495059 DOI: 10.1002/glia.24316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 11/19/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022]
Abstract
Signal propagation is the essential function of nerves. Lysophosphatidic acid 18:1 (LPA) allows the selective stimulation of calcium signaling in Schwann cells but not neurons. Here, the time course of slowing and amplitude reduction on compound action potentials due to LPA exposure was observed in myelinated and unmyelinated fibers of the mouse, indicating a clear change of axonal function. Teased nerve fiber imaging showed that Schwann cell activation is also present in axon-attached Schwann cells in freshly isolated peripheral rat nerves. The LPA receptor 1 was primarily localized at the cell extensions in isolated rat Schwann cells, suggesting a role in cell migration. Structural investigation of rat C-fibers demonstrated that LPA leads to an evagination of the axons from their Schwann cells. In A-fibers, the nodes of Ranvier appeared unchanged, but the Schmidt-Lanterman incisures were shortened and myelination reduced. The latter might increase leak current, reducing the potential spread to the next node of Ranvier and explain the changes in conduction velocity. The observed structural changes provide a plausible explanation for the functional changes in myelinated and unmyelinated axons of peripheral nerves and the reported sensory sensations such as itch and pain.
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Affiliation(s)
- Cosmin I Ciotu
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Katrin Kistner
- Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Ulrich Kaindl
- Department of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Flavia Millesi
- Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria
| | - Tamara Weiss
- Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria
| | - Christine Radtke
- Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria
| | - Andreas Kremer
- Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Katy Schmidt
- Department of Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Michael J M Fischer
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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6
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Li Q, Qiao W, Hao J, Wei S, Li X, Liu T, Qiu C, Hu W. Potentiation of ASIC currents by lysophosphatidic acid in rat dorsal root ganglion neurons. J Neurochem 2022; 163:327-337. [DOI: 10.1111/jnc.15690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/08/2022] [Accepted: 08/11/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Qing Li
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
| | - Wen‐Long Qiao
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
| | - Jia‐Wei Hao
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
| | - Shuang Wei
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
| | - Xue‐Mei Li
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
| | - Ting‐Ting Liu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
| | - Chun‐Yu Qiu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
| | - Wang‐Ping Hu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology Xianning Hubei China
- Hubei College of Chinese Medicine Jingzhou Hubei China
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7
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Corneal nerves and their role in dry eye pathophysiology. Exp Eye Res 2022; 222:109191. [PMID: 35850173 DOI: 10.1016/j.exer.2022.109191] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/15/2022] [Accepted: 07/11/2022] [Indexed: 12/11/2022]
Abstract
As the cornea is densely innervated, its nerves are integral not only to its structure but also to its pathophysiology. Corneal integrity depends on a protective tear film that is maintained by corneal sensation and the reflex arcs that control tearing and blinking. Furthermore, corneal nerves promote epithelial growth and local immunoregulation. Thus, corneal nerves constitute pillars of ocular surface homeostasis. Conversely, the abnormal tear film in dry eye favors corneal epithelial and nerve damage. The ensuing corneal nerve dysfunction contributes to dry eye progression, ocular pain and discomfort, and other neuropathic symptoms. Recent evidence from clinical studies and animal models highlight the significant but often overlooked neural dimension of dry eye pathophysiology. Herein, we review the anatomy and physiology of corneal nerves before exploring their role in the mechanisms of dry eye disease.
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8
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Qiao WL, Li Q, Hao JW, Wei S, Li XM, Liu TT, Qiu CY, Hu WP. Enhancement of P2X3 Receptor-Mediated Currents by Lysophosphatidic Acid in Rat Primary Sensory Neurons. Front Pharmacol 2022; 13:928647. [PMID: 35795546 PMCID: PMC9251206 DOI: 10.3389/fphar.2022.928647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
Lysophosphatidic acid (LPA), a lipid metabolite, plays a role in both neuropathic and inflammatory pain through LPA1 receptors. P2X3 receptor has also been shown to participate in these pathological processes. However, it is still unclear whether there is a link between LPA signaling and P2X3 receptors in pain. Herein, we show that a functional interaction between them in rat dorsal root ganglia (DRG) neurons. Pretreatment of LPA concentration-dependently enhanced α,β-methylene-ATP (α,β-meATP)-induced inward currents mediated by P2X3 receptors. LPA significantly increased the maximal current response of α,β-meATP, showing an upward shift of the concentration-response curve for α,β-meATP. The LPA enhancement was independent on the clamping-voltage. Enhancement of P2X3 receptor-mediated currents by LPA was prevented by the LPA1 receptor antagonist Ki16198, but not by the LPA2 receptor antagonist H2L5185303. The LPA-induced potentiation was also attenuated by intracellular dialysis of either G-protein inhibitor or protein kinase C (PKC) inhibitor, but not by Rho inhibitor. Moreover, LPA significantly changed the membrane potential depolarization and action potential burst induced by α,β-meATP in DRG neurons. Finally, LPA exacerbated α,β-meATP- induced nociceptive behaviors in rats. These results suggested that LPA potentiated the functional activity of P2X3 receptors in rat primary sensory neurons through activation of the LPA1 receptor and its downstream PKC rather than Rho signaling pathway, indicating a novel peripheral mechanism underlying the sensitization of pain.
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Affiliation(s)
- Wen-Long Qiao
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Qing Li
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Jia-Wei Hao
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Shuang Wei
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Xue-Mei Li
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Ting-Ting Liu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Chun-Yu Qiu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Wang-Ping Hu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- Hubei College of Chinese Medicine, Jingzhou, China
- *Correspondence: Wang-Ping Hu,
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9
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Zhang WX, Lin ZQ, Sun AL, Shi YY, Hong QX, Zhao GF. Curcumin Ameliorates the Experimental Diabetic Peripheral Neuropathy through Promotion of NGF Expression in Rats. Chem Biodivers 2022; 19:e202200029. [PMID: 35538560 DOI: 10.1002/cbdv.202200029] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/10/2022] [Indexed: 11/10/2022]
Abstract
Increasing evidence suggested that inhibiting the apoptosis of Schwann cells (SCs) and promoting nerve growth factor (NGF) expression in sciatic nerves play key roles in preventing the onset of diabetic peripheral neuropathy (DPN). Curcumin, a primary bioactive substance in turmeric with multiple characteristics, has been shown to have many therapeutic effects in a variety of diseases. However, curcumin is poorly studied in the DPN models. We aimed to explore the therapeutic benefits and underlying mechanism of curcumin in high fat/sugar diets joint streptozotocin (STZ)-induced DPN rat models. Sprague-Dawley (SD) rats were divided into five groups (6 rats per group), control group, DPN group, Curcumin groups (50, 100, and 150 mg/kg). Curcumin was administered intragastrically once per day for 4 continuous weeks. Body weight (BW) and fasting blood glucose (FBG) were monitored in all groups. The mechanical withdraw threshold (MWT) was measured. We also assessed neuropathic change by testing nerve conductance velocity (NCV) in sciatic nerves. TEM was applied to observe the sciatic nerves ultrastructure. The SCs apoptosis in sciatic nerves was stained using TUNEL kit. NGF contents in sciatic nerves and serum were detected using western blotting and ELISA analysis. The results showed curcumin had no obvious effect on the BW and FBG change. Curcumin (100 and 150 mg/kg) attenuated the MWT, NCV, and sciatic nerves ultrastructure in DPN rats. Curcumin (50, 100 and 150 mg/kg) reduced SCs apoptosis in sciatic nerves. In addition, curcumin at 150 mg/kg had the best efficacy in increasing protein expression of NGF in sciatic nerves and serum NGF level. Our work demonstrated that curcumin has neuroprotective effects for the treatment of DPN.
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Affiliation(s)
- Wen-Xuan Zhang
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 510120, Guangzhou, China
| | - Zi-Qiang Lin
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 510120, Guangzhou, China
| | - Ai-Ling Sun
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 510120, Guangzhou, China
| | - Yong-Yong Shi
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 510120, Guangzhou, China
| | - Qing-Xiong Hong
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 510120, Guangzhou, China
| | - Gao-Feng Zhao
- Department of Anesthesiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 510120, Guangzhou, China
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10
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Singleton JR, Foster-Palmer S, Marcus RL. Exercise as Treatment for Neuropathy in the Setting of Diabetes and Prediabetic Metabolic Syndrome: A Review of Animal Models and Human Trials. Curr Diabetes Rev 2022; 18:e230921196752. [PMID: 34561989 DOI: 10.2174/1573399817666210923125832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/21/2021] [Accepted: 05/17/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Peripheral neuropathy is among the most common complications of diabetes, but a phenotypically identical distal sensory predominant, painful axonopathy afflicts patients with prediabetic metabolic syndrome, exemplifying a spectrum of risk and continuity of pathogenesis. No pharmacological treatment convincingly improves neuropathy in the setting of metabolic syndrome, but evolving data suggest that exercise may be a promising alternative. OBJECTIVE The aim of the study was to review in depth the current literature regarding exercise treatment of metabolic syndrome neuropathy in humans and animal models, highlight the diverse mechanisms by which exercise exerts beneficial effects, and examine adherence limitations, safety aspects, modes and dose of exercise. RESULTS Rodent models that recapitulate the organismal milieu of prediabetic metabolic syndrome and the phenotype of its neuropathy provide a strong platform to dissect exercise effects on neuropathy pathogenesis. In these models, exercise reverses hyperglycemia and consequent oxidative and nitrosative stress, improves microvascular vasoreactivity, enhances axonal transport, ameliorates the lipotoxicity and inflammatory effects of hyperlipidemia and obesity, supports neuronal survival and regeneration following injury, and enhances mitochondrial bioenergetics at the distal axon. Prospective human studies are limited in scale but suggest exercise to improve cutaneous nerve regenerative capacity, neuropathic pain, and task-specific functional performance measures of gait and balance. Like other heath behavioral interventions, the benefits of exercise are limited by patient adherence. CONCLUSION Exercise is an integrative therapy that potently reduces cellular inflammatory state and improves distal axonal oxidative metabolism to ameliorate features of neuropathy in metabolic syndrome. The intensity of exercise need not improve cardinal features of metabolic syndrome, including weight, glucose control, to exert beneficial effects.
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Affiliation(s)
| | | | - Robin L Marcus
- Department Physical Therapy and Athletic Training, University of Utah, UT, United States
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11
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Akhilesh, Uniyal A, Gadepalli A, Tiwari V, Allani M, Chouhan D, Ummadisetty O, Verma N, Tiwari V. Unlocking the potential of TRPV1 based siRNA therapeutics for the treatment of chemotherapy-induced neuropathic pain. Life Sci 2022; 288:120187. [PMID: 34856209 DOI: 10.1016/j.lfs.2021.120187] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/24/2021] [Accepted: 11/24/2021] [Indexed: 01/23/2023]
Abstract
Chemotherapy-induced neuropathic pain (CINP) is among the most common clinical complications associated with the use of anti-cancer drugs. CINP occurs in nearly 68.1% of the cancer patients receiving chemotherapeutic drugs. Most of the clinically available analgesics are ineffective in the case of CINP patients as the pathological mechanisms involved with different chemotherapeutic drugs are distinct from each other. CINP triggers the somatosensory nervous system, increases the neuronal firing and activation of nociceptive mediators including transient receptor protein vanilloid 1 (TRPV1). TRPV1 is widely present in the peripheral nociceptive nerve cells and it has been reported that the higher expression of TRPV1 in DRGs serves a critical role in the potentiation of CINP. The therapeutic glory of TRPV1 is well recognized in clinics which gives a promising insight into the treatment of pain. But the adverse effects associated with some of the antagonists directed the scientists towards RNA interference (RNAi), a tool to silence gene expression. Thus, ongoing research is focused on developing small interfering RNA (siRNA)-based therapeutics targeting TRPV1. In this review, we have discussed the involvement of TRPV1 in the nociceptive signaling associated with CINP and targeting this nociceptor, using siRNA will potentially arm us with effective therapeutic interventions for the clinical management of CINP.
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Affiliation(s)
- Akhilesh
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Ankit Uniyal
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Anagha Gadepalli
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Vineeta Tiwari
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Meghana Allani
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Deepak Chouhan
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Obulapathi Ummadisetty
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Nimisha Verma
- Department of Anaesthesiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Vinod Tiwari
- Neuroscience and Pain Research Laboratory, Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
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12
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Zhao L, Tao X, Song T. Astaxanthin alleviates neuropathic pain by inhibiting the MAPKs and NF-κB pathways. Eur J Pharmacol 2021; 912:174575. [PMID: 34673033 DOI: 10.1016/j.ejphar.2021.174575] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 02/06/2023]
Abstract
Neuropathic pain is a complex condition that usually lasts a lifetime and has a major negative impact on life after injury. Improving pain management is an important and unmet need. Astaxanthin (AST) is a natural marine medicine with effective antioxidant and anti-inflammatory properties and neuroprotective effects. However, few mechanisms can explain the role of AST in the treatment of neuropathic pain. In the present study, we examined its potential to eliminate spinal nerve ligation (SNL) damage by inhibiting the phosphorylation of extracellular signal-regulated kinase (ERK)1/2, phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), nuclear factor-κB (NF-κB) p65 and the inflammatory response. The results of behavior tests indicated the promising role of AST in analgesic effect in SNL mice. AST decreased the neuronal and non-neuronal activation, the levels of the inflammatory signaling mediators (p-ERK1/2 p-p38 MAPK and NF-κB p65) and inflammatory cytokine expression (interleukin [IL]-1, IL-17, IL-6, and tumor necrosis factor-α [TNF-α]. These results suggest that AST is a promising candidate to reduce nociceptive hypersensitization after SNL.
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Affiliation(s)
- Lin Zhao
- Department of Pain, The First Affiliated Hospital to China Medical University, Shen Yang, China
| | - Xueshu Tao
- Department of Pain, The First Affiliated Hospital to China Medical University, Shen Yang, China
| | - Tao Song
- Department of Pain, The First Affiliated Hospital to China Medical University, Shen Yang, China.
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13
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Gao L, Zhang JF, Williams JP, Yan YN, Xiao XL, Shi WR, Qian XY, An JX. Neuropathic Pain Creates Systemic Ultrastructural Changes in the Nervous System Corrected by Electroacupuncture but Not by Pregabalin. J Pain Res 2021; 14:2893-2905. [PMID: 34548816 PMCID: PMC8449649 DOI: 10.2147/jpr.s322964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/28/2021] [Indexed: 12/30/2022] Open
Abstract
Purpose It is unclear whether neuropathological structural changes in the peripheral nervous system and central nervous system can occur in the spared nerve injury model. In this study, we investigated the pathological changes in the nervous system in a model of neuropathic pain as well as the effects of electroacupuncture (EA) and pregabalin (PGB) administration as regards pain relief and tissue repair. Patients and Methods Forty adult male SD rats were equally and randomly divided into 4 groups: spared nerve injury group (SNI, n = 10), SNI with electroacupuncture group (EA, n = 10), SNI with pregabalin group (PGB, n =10) and sham-operated group (Sham, n=10). EA and PGB were given from postoperative day (POD) 14 to 36. EA (2 Hz and 100 Hz alternating frequencies, intensities ranging from 1–1.5–2 mA) was applied to the left “zusanli” (ST36) and “Yanglingquan” (GB34) acupoints for 30 minutes. The mechanical withdrawal thresholds (MWTs) were tested with von Frey filaments. Moreover, the organizational and structural alterations of the bilateral prefrontal cortex, hippocampus, sciatic nerves and the thoracic, lumbar spinal cords and dorsal root ganglions (DRGs) were examined via light and electron microscopy. Results MWTs of left hind paw demonstrated a remarkable decrease in the SNI model (P < 0.05). In the SNI model, ultrastructural changes including demyelination and damaged neurons were observed at all levels of the peripheral nervous system (PNS) and central nervous system (CNS). In addition, EA improved MWTs and restored the normal structure of neurons. However, the effect was not found in the PGB treatment group. Conclusion Chronic pain can induce extensive damage to the central and peripheral nervous systems. Meanwhile, EA and PGB can both alleviate chronic pain syndromes in rats, but EA also restores the normal cellular structures, while PGB is associated with no improvement.
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Affiliation(s)
- Lei Gao
- Department of Anesthesiology, Pain and Sleep Medicine, Aviation General Hospital of China Medical University and Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Anesthesiology, Weifang Medical University, Weifang, Shangdong, People's Republic of China
| | - Jian-Feng Zhang
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - John P Williams
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Yi-Ning Yan
- Department of Anesthesiology, Pain and Sleep Medicine, Aviation General Hospital of China Medical University and Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Xi-Lai Xiao
- Department of Anesthesiology, Pain and Sleep Medicine, Aviation General Hospital of China Medical University and Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Wan-Rui Shi
- Department of Anesthesiology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Xiao-Yan Qian
- Department of Anesthesiology, Pain and Sleep Medicine, Aviation General Hospital of China Medical University and Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Jian-Xiong An
- Department of Anesthesiology, Pain and Sleep Medicine, Aviation General Hospital of China Medical University and Beijing Institute of Translational Medicine, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Anesthesiology, Weifang Medical University, Weifang, Shangdong, People's Republic of China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Medical Science & Engineering, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, People's Republic of China
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14
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Ding YQ, Qi JG. Sensory root demyelination: Transforming touch into pain. Glia 2021; 70:397-413. [PMID: 34549463 DOI: 10.1002/glia.24097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 11/12/2022]
Abstract
The normal feeling of touch is vital for nearly every aspect of our daily life. However, touching is not always felt as touch, but also abnormally as pain under numerous diseased conditions. For either mechanistic understanding of the faithful feeling of touch or clinical management of chronic pain, there is an essential need to thoroughly dissect the neuropathological changes that lead to painful touch or tactile allodynia and their corresponding cellular and molecular underpinnings. In recent years, we have seen remarkable progress in our understanding of the neural circuits for painful touch, with an increasing emphasis on the upstream roles of non-neuronal cells. As a highly specialized form of axon ensheathment by glial cells in jawed vertebrates, myelin sheaths not only mediate their outstanding neural functions via saltatory impulse propagation of temporal and spatial precision, but also support long-term neuronal/axonal integrity via metabolic and neurotrophic coupling. Therefore, myelinopathies have been implicated in diverse neuropsychiatric diseases, which are traditionally recognized as a result of the dysfunctions of neural circuits. However, whether myelinopathies can transform touch into pain remains a long-standing question. By summarizing and reframing the fragmentary but accumulating evidence so far, the present review indicates that sensory root demyelination represents a hitherto underappreciated neuropathological change for most neuropathic conditions of painful touch and offers an insightful window into faithful tactile sensation as well as a potential therapeutic target for intractable painful touch.
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Affiliation(s)
- You-Quan Ding
- Department of Histology, Embryology and Neurobiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Jian-Guo Qi
- Department of Histology, Embryology and Neurobiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
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15
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Khoury AL, Keane H, Varghese F, Hosseini A, Mukhtar R, Eder SE, Weinstein PR, Esserman LJ. Trigger point injection for post-mastectomy pain: a simple intervention with high rate of long-term relief. NPJ Breast Cancer 2021; 7:123. [PMID: 34535677 PMCID: PMC8448876 DOI: 10.1038/s41523-021-00321-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 08/12/2021] [Indexed: 11/08/2022] Open
Abstract
Post-mastectomy pain syndrome (PMPS) is a common and often debilitating condition. The syndrome is defined by chest wall pain unresponsive to standard pain medications and the presence of exquisite point tenderness along the inframammary fold at the site of the T4 and T5 cutaneous intercostal nerve branches as they exit from the chest wall. Pressure at the site triggers and reproduces the patient's spontaneous or motion-evoked pain. The likely pathogenesis is neuroma formation after injury to the T4 and T5 intercostal nerves during breast surgery. We assessed the rate of long-term resolution of post-mastectomy pain after trigger point injections (2 mL of 1:1 mixture of 0.5% bupivacaine and 4 mg/mL dexamethasone) to relieve neuropathic pain in a prospective single-arm cohort study. Fifty-two women (aged 31-92) who underwent partial mastectomy with reduction mammoplasty or mastectomy with or without reconstruction, and who presented with PMPS were enrolled at the University of California San Francisco Breast Care Center from August 2010 through April 2018. The primary outcome was a long-term resolution of pain, defined as significant or complete relief of pain for greater than 3 months. A total of 91 trigger points were treated with mean follow-up 43.9 months with a 91.2% (83/91) success rate. Among those with a long-term resolution of pain, 60 trigger points (72.3%) required a single injection to achieve long-lasting relief. Perineural infiltration with bupivacaine and dexamethasone is a safe, simple, and effective treatment for PMPS presenting as trigger point pain along the inframammary fold.
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Affiliation(s)
- Amal L Khoury
- Department of Surgery, University of California San Francisco, East Bay - Highland Hospital, Oakland, CA, USA
| | - Holly Keane
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Flora Varghese
- General Surgery, Adventist Health and Rideout, Yuba City, CA, USA
| | - Ava Hosseini
- Department of Surgery, University of California-San Diego, San Diego, CA, USA
| | - Rita Mukhtar
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Suzanne E Eder
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Philip R Weinstein
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Laura J Esserman
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA.
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16
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Krajnak K. Vibrotactile sensitivity testing for occupational and disease-induce peripheral neuropathies. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2021; 24:162-172. [PMID: 33719930 DOI: 10.1080/10937404.2021.1897911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The International Standard Organization (ISO) standard 13091-1 describes methods and procedures for performing the vibrotactile perception threshold (VPT) testing to diagnose changes in tactile sensory function associated with occupational exposures. However, the VPT test also has been used in the diagnosis of peripheral neuropathies associated with a number of disorders. This review examines the VPT test, variations in procedures that have been used, as well as disorders and diseases in which this test has been reliable for the detection of sensory changes. Mechanisms potentially underlying the changes in VPTs are also discussed along with procedural and subject/patient factors that may affect the interpretation of test results. Based upon the review of the literature, there are also suggestions for where additional research might improve the administration of this test, depending upon the subject/patient population and interpretation of data.
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Affiliation(s)
- Kristine Krajnak
- Physical Effect Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
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17
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He FL, Qiu S, Zou JL, Gu FB, Yao Z, Tu ZH, Wang YY, Liu XL, Zhou LH, Zhu QT. Covering the proximal nerve stump with chondroitin sulfate proteoglycans prevents traumatic painful neuroma formation by blocking axon regeneration after neurotomy in Sprague Dawley rats. J Neurosurg 2021; 134:1599-1609. [PMID: 32470939 DOI: 10.3171/2020.3.jns193202] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 03/06/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Neuropathic pain caused by traumatic neuromas is an extremely intractable clinical problem. Disorderly scar tissue accumulation and irregular and immature axon regeneration around the injury site mainly contribute to traumatic painful neuroma formation. Therefore, successfully preventing traumatic painful neuroma formation requires the effective inhibition of irregular axon regeneration and disorderly accumulation of scar tissue. Considering that chondroitin sulfate proteoglycans (CSPGs) can act on the growth cone and effectively inhibit axon regeneration, the authors designed and manufactured a CSPG-gelatin blocker to regulate the CSPGs' spatial distribution artificially and applied it in a rat model after sciatic nerve neurectomy to evaluate its effects in preventing traumatic painful neuroma formation. METHODS Sixty female Sprague Dawley rats were randomly divided into three groups (positive group: no covering; blank group: covering with gelatin blocker; and CSPG group: covering with the CSPG-gelatin blocker). Pain-related factors were evaluated 2 and 8 weeks postoperatively (n = 30). Neuroma growth, autotomy behavior, and histological features of the neuromas were assessed 8 weeks postoperatively (n = 30). RESULTS Eight weeks postoperatively, typical bulb-shaped neuromas did not form in the CSPG group, and autotomy behavior was obviously better in the CSPG group (p < 0.01) than in the other two groups. Also, in the CSPG group the regenerated axons showed a lower density and more regular and improved myelination (p < 0.01). Additionally, the distribution and density of collagenous fibers and the expression of α-smooth muscle actin were significantly lower in the CSPG group than in the positive group (p < 0.01). Regarding pain-related factors, c-fos, substance P, interleukin (IL)-17, and IL-1β levels were significantly lower in the CSPG group than those in the positive and blank groups 2 weeks postoperatively (p < 0.05), while substance P and IL-17 remained lower in the CSPG group 8 weeks postoperatively (p < 0.05). CONCLUSIONS The authors found that CSPGs loaded in a gelatin blocker can prevent traumatic neuroma formation and effectively relieve pain symptoms after sciatic nerve neurotomy by blocking irregular axon regeneration and disorderly collagenous fiber accumulation in the proximal nerve stump. These results indicate that covering the proximal nerve stump with CSPGs may be a new and promising strategy to prevent traumatic painful neuroma formation in the clinical setting.
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Affiliation(s)
- Fu-Lin He
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
- 2Center for Peripheral Nerve Tissue Engineering and Technology Research
| | - Shuai Qiu
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
- 2Center for Peripheral Nerve Tissue Engineering and Technology Research
| | - Jian-Long Zou
- 3School of Basic Medical Sciences, Guangzhou Medical University
| | - Fan-Bin Gu
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
- 2Center for Peripheral Nerve Tissue Engineering and Technology Research
| | - Zhi Yao
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
- 2Center for Peripheral Nerve Tissue Engineering and Technology Research
| | - Zhe-Hui Tu
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
| | - Yuan-Yuan Wang
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
| | - Xiao-Lin Liu
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
- 2Center for Peripheral Nerve Tissue Engineering and Technology Research
- 4Guangdong Province Engineering Laboratory for Soft Tissue Biofabrication; and
| | - Li-Hua Zhou
- 5Department of Anatomy, School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Qing-Tang Zhu
- 1Department of Microsurgery and Orthopedic Trauma, First Affiliated Hospital of Sun Yat-sen University, Guangzhou
- 2Center for Peripheral Nerve Tissue Engineering and Technology Research
- 4Guangdong Province Engineering Laboratory for Soft Tissue Biofabrication; and
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18
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Uranbileg B, Ito N, Kurano M, Kano K, Uchida K, Sumitani M, Aoki J, Yatomi Y. Inhibition of autotaxin activity ameliorates neuropathic pain derived from lumbar spinal canal stenosis. Sci Rep 2021; 11:3984. [PMID: 33597645 PMCID: PMC7889906 DOI: 10.1038/s41598-021-83569-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/04/2021] [Indexed: 12/13/2022] Open
Abstract
Lumbar spinal canal stenosis (LSS) or mechanical compression of dorsal root ganglion (DRG) is one of the causes of low back pain and neuropathic pain (NP). Lysophosphatidic acid (LPA) is a potent bioactive lipid mediator that is produced mainly from lysophosphatidylcholine (LPC) via autotaxin (ATX) and is known to induce NP via LPA1 receptor signaling in mice. Recently, we demonstrated that LPC and LPA were higher in cerebrospinal fluid (CSF) of patients with LSS. Based on the possible potential efficacy of the ATX inhibitor for NP treatment, we used an NP model with compression of DRG (CD model) and investigated LPA dynamics and whether ATX inhibition could ameliorate NP symptoms, using an orally available ATX inhibitor (ONO-8430506) at a dose of 30 mg/kg. In CD model, we observed increased LPC and LPA levels in CSF, and decreased threshold of the pain which were ameliorated by oral administration of the ATX inhibitor with decreased microglia and astrocyte populations at the site of the spinal dorsal horn projecting from injured DRG. These results suggested possible efficacy of ATX inhibitor for the treatment of NP caused by spinal nerve root compression and involvement of the ATX-LPA axis in the mechanism of NP induction.
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Affiliation(s)
- Baasanjav Uranbileg
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo, Japan
| | - Nobuko Ito
- Department of Anesthesiology and Pain Relief Center, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
| | - Makoto Kurano
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo, Japan
| | - Kuniyuki Kano
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kanji Uchida
- Department of Anesthesiology and Pain Relief Center, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Masahiko Sumitani
- Department of Pain and Palliative Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Junken Aoki
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo, Japan
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19
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Liu M, Xie Z, Costello CA, Zhang W, Chen L, Qi D, Furey A, Randell EW, Rahman P, Zhai G. Metabolomic analysis coupled with extreme phenotype sampling identified that lysophosphatidylcholines are associated with multisite musculoskeletal pain. Pain 2021; 162:600-608. [PMID: 32833795 PMCID: PMC7808366 DOI: 10.1097/j.pain.0000000000002052] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/07/2020] [Accepted: 08/11/2020] [Indexed: 12/18/2022]
Abstract
ABSTRACT Musculoskeletal pain often occurs simultaneously at multiple anatomical sites. The aim of the study was to identify metabolic biomarkers for multisite musculoskeletal pain (MSMP) by metabolomics with an extreme phenotype sampling strategy. The study participants (n = 610) were derived from the Newfoundland Osteoarthritis Study. Musculoskeletal pain was assessed using a self-reported pain questionnaire where painful sites were circled on a manikin by participants and the total number of painful sites were calculated. Targeted metabolomic profiling on fasting plasma samples was performed using the Biocrates AbsoluteIDQ p180 kit. Plasma cytokine concentrations including tumor necrosis factor-α, interleukin-6, interleukin-1β, and macrophage migration inhibitory factor were assessed by enzyme-linked immunosorbent assay. Data on blood cholesterol profiles were retrieved from participants' medical records. Demographic, anthropological, and clinical information was self-reported. The number of reported painful sites ranged between 0 and 21. Two hundred and five participants were included in the analysis comprising 83 who had ≥7 painful sites and 122 who had ≤1 painful site. Women and younger people were more likely to have MSMP (P ≤ 0.02). Multisite musculoskeletal pain was associated with a higher risk of having incontinence, worse functional status and longer period of pain, and higher levels of low-density lipoprotein and non-high-density lipoprotein cholesterol (all P ≤ 0.03). Among the 186 metabolites measured, 2 lysophosphatidylcholines, 1 with 26 carbons with no double bond and 1 with 28 carbons with 1 double bond, were significantly and positively associated with MSMP after adjusting for multiple testing with the Bonferroni method (P ≤ 0.0001) and could be considered as novel metabolic markers for MSMP.
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Affiliation(s)
- Ming Liu
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Zikun Xie
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
| | - Christie A. Costello
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Weidong Zhang
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
- School of Pharmaceutical Sciences, Jilin University, Changchun, China
| | - Liujun Chen
- College of Pharmacy, University of Manitoba, Winnipeg, Canada
| | - Dake Qi
- College of Pharmacy, University of Manitoba, Winnipeg, Canada
| | - Andrew Furey
- Discipline of Surgery, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Edward W. Randell
- Discipline of Laboratory Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Proton Rahman
- Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Guangju Zhai
- Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
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20
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Ueda H, Dozono N, Tanaka K, Kaneko S, Neyama H, Uchida H. Allodynia by Splenocytes From Mice With Acid-Induced Fibromyalgia-Like Generalized Pain and Its Sexual Dimorphic Regulation by Brain Microglia. Front Neurosci 2021; 14:600166. [PMID: 33424538 PMCID: PMC7785978 DOI: 10.3389/fnins.2020.600166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/24/2020] [Indexed: 12/23/2022] Open
Abstract
Fibromyalgia (FM), a disease of unknown etiology characterized by chronic generalized pain, is partly recapitulated in an animal model induced by repeated acid saline injections into the gastrocnemius muscle. Here, we attempted to investigate the sex difference in pain hypersensitivity (mechanical allodynia and hypersensitivity to electrical stimulation) in the repeated acid saline-induced FM-like generalized pain (AcGP) model. The first unilateral acid injection into gastrocnemius muscle at day 0/D0 and second injection at D5 (post day 0, P0) induced transient and long-lasting mechanical allodynia, respectively, on both sides of male and female mice. The pretreatment with gonadectomy did not affect the first injection-induced allodynia in both sexes, but gradually reversed the second injection-induced allodynia in male but not female mice. Moreover, the AcGP in male mice was abolished by intracerebroventricular minocycline treatments during D4–P4 or P5–P11, but not by early treatments during D0–D5 in male but not female mice, suggesting that brain microglia are required for AcGP in late-onset and sex-dependent manners. We also found that the intravenous treatments of splenocytes derived from male but not female mice treated with AcGP caused allodynia in naive mice. In addition, the purified CD4+ T cells derived from splenocytes of acid-treated male mice retained the ability to cause allodynia in naive mice. These findings suggest that FM-like AcGP has multiple sexual dimorphic mechanisms.
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Affiliation(s)
- Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Institute of Biomedical Sciences, Nagasaki, Japan.,Department of Molecular Pharmacology, Kyoto University Graduate School of Pharmaceutical Sciences, Kyoto, Japan
| | - Naoki Dozono
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Institute of Biomedical Sciences, Nagasaki, Japan.,Department of Molecular Pharmacology, Kyoto University Graduate School of Pharmaceutical Sciences, Kyoto, Japan
| | - Keigo Tanaka
- Department of Molecular Pharmacology, Kyoto University Graduate School of Pharmaceutical Sciences, Kyoto, Japan
| | - Shuji Kaneko
- Department of Molecular Pharmacology, Kyoto University Graduate School of Pharmaceutical Sciences, Kyoto, Japan
| | - Hiroyuki Neyama
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Institute of Biomedical Sciences, Nagasaki, Japan.,RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Hitoshi Uchida
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Institute of Biomedical Sciences, Nagasaki, Japan.,Department of Cellular Neuropathology, Brain Research Institute, Niigata University, Niigata, Japan
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21
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Wang X, Li Q, Han X, Gong M, Yu Z, Xu B. Electroacupuncture Alleviates Diabetic Peripheral Neuropathy by Regulating Glycolipid-Related GLO/AGEs/RAGE Axis. Front Endocrinol (Lausanne) 2021; 12:655591. [PMID: 34295304 PMCID: PMC8290521 DOI: 10.3389/fendo.2021.655591] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 05/19/2021] [Indexed: 01/04/2023] Open
Abstract
Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus (DM) and affects over one-third of all patients. Neuropathic pain and nerve dysfunction induced by DM is related to the increase of advanced glycation end products (AGEs) produced by reactive dicarbonyl compounds in a hyperglycemia environment. AGEs induce the expression of pro-inflammatory cytokines via the main receptor (RAGE), which has been documented to play a crucial role in the pathogenesis of diabetic peripheral neuropathy. Electroacupuncture (EA) has been reported to have a positive effect on paralgesia caused by various diseases, but the mechanism is unclear. In this study, we used high-fat-fed low-dose streptozotocin-induced rats as a model of type 2 diabetes (T2DM). Persistent metabolic disorder led to mechanical and thermal hyperalgesia, as well as intraepidermal nerve fiber density reduction and nerve demyelination. EA improved neurological hyperalgesia, decreased the pro-inflammatory cytokines, reduced the generation of AGEs and RAGE, and regulated the glyoxalase system in the EA group. Taken together, our study suggested that EA plays a role in the treatment of T2DM-induced DPN, and is probably related to the regulation of metabolism and the secondary influence on the GLO/AGE/RAGE axis.
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Affiliation(s)
| | | | | | | | - Zhi Yu
- *Correspondence: Zhi Yu, ; Bin Xu,
| | - Bin Xu
- *Correspondence: Zhi Yu, ; Bin Xu,
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22
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Pathogenic mechanisms of lipid mediator lysophosphatidic acid in chronic pain. Prog Lipid Res 2020; 81:101079. [PMID: 33259854 DOI: 10.1016/j.plipres.2020.101079] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
A number of membrane lipid-derived mediators play pivotal roles in the initiation, maintenance, and regulation of various types of acute and chronic pain. Acute pain, comprising nociceptive and inflammatory pain warns us about the presence of damage or harmful stimuli. However, it can be efficiently reversed by opioid analgesics and anti-inflammatory drugs. Prostaglandin E2 and I2, the representative lipid mediators, are well-known causes of acute pain. However, some lipid mediators such as lipoxins, resolvins or endocannabinoids suppress acute pain. Various types of peripheral and central neuropathic pain (NeuP) as well as fibromyalgia (FM) are representatives of chronic pain and refractory owing to abnormal pain processing distinct from acute pain. Accumulating evidence demonstrated that lipid mediators represented by lysophosphatidic acid (LPA) are involved in the initiation and maintenance of both NeuP and FM in experimental animal models. The LPAR1-mediated peripheral mechanisms including dorsal root demyelination, Cavα2δ1 expression in dorsal root ganglion, and LPAR3-mediated amplification of central LPA production via glial cells are involved in the series of molecular mechanisms underlying NeuP. This review also discusses the involvement of lipid mediators in emerging research directives, including itch-sensing, sexual dimorphism, and the peripheral immune system.
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Brifault C, Romero H, Van-Enoo A, Pizzo D, Azmoon P, Kwon H, Nasamran C, Gonias SL, Campana WM. Deletion of the Gene Encoding the NMDA Receptor GluN1 Subunit in Schwann Cells Causes Ultrastructural Changes in Remak Bundles and Hypersensitivity in Pain Processing. J Neurosci 2020; 40:9121-9136. [PMID: 33051351 PMCID: PMC7672997 DOI: 10.1523/jneurosci.0663-20.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 09/24/2020] [Accepted: 10/04/2020] [Indexed: 12/19/2022] Open
Abstract
Abnormalities in interactions between sensory neurons and Schwann cells (SCs) may result in heightened pain processing and chronic pain states. We previously reported that SCs express the NMDA receptor (NMDA-R), which activates cell signaling in response to glutamate and specific protein ligands, such as tissue-type plasminogen activator. Herein, we genetically targeted grin1 encoding the essential GluN1 NMDA-R subunit, conditionally in SCs, to create a novel mouse model in which SCs are NMDA-R-deficient (GluN1- mice). These mice demonstrated increased sensitivity to light touch, pinprick, and thermal hyperalgesia in the absence of injury, without associated changes in motor function. Ultrastructural analysis of adult sciatic nerve in GluN1- mice revealed increases in the density of Aδ fibers and Remak bundles and a decrease in the density of Aβ fibers, without altered g-ratios. Abnormalities in adult Remak bundle ultrastructure were also present including aberrant C-fiber ensheathment, distances between axons, and increased poly-axonal pockets. Developmental and post radial sorting defects contributed to altered nerve fiber densities in adult. Uninjured sciatic nerves in GluN1- mice did not demonstrate an increase in neuroinflammatory infiltrates. Transcriptome profiling of dorsal root ganglia (DRGs) revealed 138 differentially regulated genes in GluN1- mice. One third of the regulated genes are known to be involved in pain processing, including sprr1a, npy, fgf3, atf3, and cckbr, which were significantly increased. The intraepidermal nerve fiber density (IENFD) was significantly decreased in the skin of GluN1- mice. Collectively, these findings demonstrate that SC NMDA-R is essential for normal PNS development and for preventing development of pain states.SIGNIFICANCE STATEMENT Chronic unremitting pain is a prevalent medical condition; however, the molecular mechanisms that underlie heightened pain processing remain incompletely understood. Emerging data suggest that abnormalities in Schwann cells (SCs) may cause neuropathic pain. We established a novel mouse model for small fiber neuropathy (SFN) in which grin1, the gene that encodes the NMDA receptor (NMDA-R) GluN1 subunit, is deleted in SCs. These mice demonstrate hypersensitivity in pain processing in the absence of nerve injury. Changes in the density of intraepidermal small fibers, the ultrastructure of Remak bundles, and the transcriptome of dorsal root ganglia (DRGs) provide possible explanations for the increase in pain processing. Our results support the hypothesis that abnormalities in communication between sensory nerve fibers and SCs may result in pain states.
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Affiliation(s)
- Coralie Brifault
- Department of Anesthesiology, University of California San Diego, La Jolla, California 92093
- Department of Pathology, University of California San Diego, La Jolla, California 92093
| | - Haylie Romero
- Department of Anesthesiology, University of California San Diego, La Jolla, California 92093
- Program in Neurosciences, University of California, San Diego, La Jolla, California 92093
| | - Alicia Van-Enoo
- Department of Anesthesiology, University of California San Diego, La Jolla, California 92093
- Program in Neurosciences, University of California, San Diego, La Jolla, California 92093
| | - Don Pizzo
- Department of Pathology, University of California San Diego, La Jolla, California 92093
| | - Pardis Azmoon
- Department of Pathology, University of California San Diego, La Jolla, California 92093
| | - HyoJun Kwon
- Department of Anesthesiology, University of California San Diego, La Jolla, California 92093
| | - Chanond Nasamran
- Center for Computational Biology and Bioinformatics, Department of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Steven L Gonias
- Department of Pathology, University of California San Diego, La Jolla, California 92093
| | - Wendy M Campana
- Department of Anesthesiology, University of California San Diego, La Jolla, California 92093
- Program in Neurosciences, University of California, San Diego, La Jolla, California 92093
- San Diego Veterans Administration Health Care System, San Diego, California 92161
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Yu H, Toume K, Kurokawa Y, Andoh T, Komatsu K. Iridoids isolated from Viticis Fructus inhibit paclitaxel-induced mechanical allodynia in mice. J Nat Med 2020; 75:48-55. [PMID: 32816150 DOI: 10.1007/s11418-020-01441-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/29/2020] [Indexed: 01/07/2023]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) manifests as mechanical allodynia and hyperalgesia, and is one of the main adverse effects of chemotherapeutic agents. Currently available therapeutic drugs are not sufficiently effective for the management of this adverse effect in the clinic. Therefore, the development of novel therapeutic agents for treating CIPN is necessary. Our previous study suggested the potential of aucubin and pedicularis-lactone (1) as active compounds responsible for the anti-allodynic property of Plantaginis Semen. However, the activity of purified 1 has not been evaluated due to its low content in Plantaginis Semen. In the present study, 1 was isolated from Viticis Fructus, as well as viteoid I (2) and viteoid II (3) during the process of isolation. The purities of isolated 1, 2, and 3 were determined as 67.15%, 92.12%, and 86.72%, respectively, by quantitative 1H-NMR, using DSS-d6 as an internal standard. Repeated daily oral administration of these three iridoids at a dose of 15 mg/kg significantly inhibited the PTX-induced mechanical allodynia in mice, suggesting the anti-allodynic activities of 1, 2, and 3. This study provides confirmatory evidence for the anti-allodynic activity of purified 1 and also reveals two additional active iridoids from Viticis Fructus. These three iridoids could be potential candidates for the treatment of CIPN.
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Affiliation(s)
- Huanhuan Yu
- Section of Pharmacognosy, Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
| | - Kazufumi Toume
- Section of Pharmacognosy, Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan.
| | - Yoko Kurokawa
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
| | - Tsugunobu Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan.,Department of Pharmacology and Pathophysiology, College of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyama-ku, Nagoya, Aichi, 463-8521, Japan
| | - Katsuko Komatsu
- Section of Pharmacognosy, Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan.
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Lysophosphatidic Acid Receptor 1- and 3-Mediated Hyperalgesia and Hypoalgesia in Diabetic Neuropathic Pain Models in Mice. Cells 2020; 9:cells9081906. [PMID: 32824296 PMCID: PMC7465054 DOI: 10.3390/cells9081906] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/08/2020] [Accepted: 08/13/2020] [Indexed: 12/28/2022] Open
Abstract
Lysophosphatidic acid (LPA) signaling is known to play key roles in the initiation and maintenance of various chronic pain models. Here we examined whether LPA signaling is also involved in diabetes-induced abnormal pain behaviors. The high-fat diet (HFD) showing elevation of blood glucose levels and body weight caused thermal, mechanical hyperalgesia, hypersensitivity to 2000 or 250 Hz electrical-stimulation and hyposensitivity to 5 Hz stimulation to the paw in wild-type (WT) mice. These HFD-induced abnormal pain behaviors and body weight increase, but not elevated glucose levels were abolished in LPA1−/− and LPA3−/− mice. Repeated daily intrathecal (i.t.) treatments with LPA1/3 antagonist AM966 reversed these abnormal pain behaviors. Similar abnormal pain behaviors and their blockade by daily AM966 (i.t.) or twice daily Ki16425, another LPA1/3 antagonist was also observed in db/db mice which show high glucose levels and body weight. Furthermore, streptozotocin-induced similar abnormal pain behaviors, but not elevated glucose levels or body weight loss were abolished in LPA1−/− and LPA3−/− mice. These results suggest that LPA1 and LPA3 play key roles in the development of both type I and type II diabetic neuropathic pain.
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Neyama H, Dozono N, Uchida H, Ueda H. Mirtazapine, an α2 Antagonist-Type Antidepressant, Reverses Pain and Lack of Morphine Analgesia in Fibromyalgia-Like Mouse Models. J Pharmacol Exp Ther 2020; 375:1-9. [PMID: 32665319 DOI: 10.1124/jpet.120.265942] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 07/13/2020] [Indexed: 12/16/2022] Open
Abstract
Treatment of fibromyalgia is an unmet medical need; however, its pathogenesis is still poorly understood. In a series of studies, we have demonstrated that some pharmacological treatments reverse generalized chronic pain but do not affect the lack of morphine analgesia in the intermittent cold stress (ICS)-induced fibromyalgia-like pain model in mice. Here we report that repeated intraperitoneal treatments with mirtazapine, which is presumed to disinhibit 5-hydroxytriptamine (5-HT) release and activate 5-HT1 receptor through mechanisms of blocking presynaptic adrenergic α2 and postsynaptic 5-HT2 and 5-HT3 receptors, completely reversed the chronic pain for more than 4 to 5 days after the cessation of treatments. The repeated mirtazapine treatments also recovered the morphine analgesia after the return of nociceptive threshold to the normal level. The microinjection of small interfering RNA (siRNA) adrenergic α2a receptor (ADRA2A) into the habenula, which showed a selective upregulation of α2 receptor gene expression after ICS, reversed the hyperalgesia but did not recover the morphine analgesia. However, both reversal of hyperalgesia and recovery of morphine analgesia were observed when siRNA ADRA2A was administered intracerebroventricularly. As the habenular is reported to be involved in the emotion/reward-related pain and hypoalgesia, these results suggest that mirtazapine could attenuate pain and/or augment hypoalgesia by blocking the habenular α2 receptor after ICS. The recovery of morphine analgesia in the ICS model, on the other hand, seems to be mediated through a blockade of α2 receptor in unidentified brain regions. SIGNIFICANCE STATEMENT: This study reports possible mechanisms underlying the complete reversal of hyperalgesia and recovery of morphine analgesia by mirtazapine, a unique antidepressant with adrenergic α2 and serotonergic receptor antagonist properties, in a type of intermittently repeated stress (ICS)-induced fibromyalgia-like pain model. Habenula, a brain region which is related to the control of emotional pain, was found to play key roles in the antihyperalgesia, whereas other brain regions appeared to be involved in the recovery of morphine analgesia in the ICS model.
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Affiliation(s)
- Hiroyuki Neyama
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Naoki Dozono
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Hitoshi Uchida
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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27
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Mechanical allodynia in mice with tenascin-X deficiency associated with Ehlers-Danlos syndrome. Sci Rep 2020; 10:6569. [PMID: 32300146 PMCID: PMC7162960 DOI: 10.1038/s41598-020-63499-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/07/2020] [Indexed: 12/22/2022] Open
Abstract
Tenascin-X (TNX) is a member of the extracellular matrix glycoprotein tenascin family, and TNX deficiency leads to Ehlers-Danlos syndrome, a heritable human disorder characterized mostly by skin hyperextensibility, joint hypermobility, and easy bruising. TNX-deficient patients complain of chronic joint pain, myalgia, paresthesia, and axonal polyneuropathy. However, the molecular mechanisms by which TNX deficiency complicates pain are unknown. Here, we examined the nociceptive behavioral responses of TNX-deficient mice. Compared with wild-type mice, TNX-deficient mice exhibited mechanical allodynia but not thermal hyperalgesia. TNX deficiency also increased pain sensitivity to chemical stimuli and aggravated early inflammatory pain elicited by formalin. TNX-deficient mice were significantly hypersensitive to transcutaneous sine wave stimuli at frequencies of 250 Hz (Aδ fiber responses) and 2000 Hz (Aβ fiber responses), but not to stimuli at frequency of 5 Hz (C fiber responses). In addition, the phosphorylation levels of extracellular signal-related kinase, an active neuronal marker, and the activity of NADPH-diaphorase, a neuronal nitric oxide activation marker, were enhanced in the spinal dorsal horns of TNX-deficient mice. These results suggest that TNX deficiency contributes to the development of mechanical allodynia and hypersensitivity to chemical stimuli, and it induces hypersensitization of myelinated A fibers and activation of the spinal dorsal horn.
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28
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Kondo M, Shibuta I. Extracellular signal-regulated kinases (ERK) 1 and 2 as a key molecule in pain research. J Oral Sci 2020; 62:147-149. [PMID: 32224567 DOI: 10.2334/josnusd.19-0470] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Pain can be divided into nociceptive, inflammatory, and neuropathic pain. It is important to understanding the molecular mechanism of pain signaling in the development of pain relief therapies. Twenty years ago, extracellular signal-regulated kinases (ERK) 1 and 2, which are members of the mitogen-activated protein kinase superfamily, were identified as molecules activated in neurons by the exposure of peripheral tissues to noxious stimuli. Further studies have revealed that peripheral nerve injury induces ERK activation in glial cells, sensory neurons, and second-order neurons, albeit at different time points. Moreover, inhibition of ERK suppresses pathological pain in animals with peripheral nerve injury. Therefore, ERK is currently recognized as an important molecule in pain signaling and a potential novel target for pain treatment. This review introduces recent advances in revealing the regulation of ERK in pain research.
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Affiliation(s)
- Masahiro Kondo
- Department of Legal Medicine, Nihon University School of Dentistry
| | - Ikuko Shibuta
- Department of Physiology, Nihon University School of Dentistry
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29
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Liu YP, Shao SJ, Guo HD. Schwann cells apoptosis is induced by high glucose in diabetic peripheral neuropathy. Life Sci 2020; 248:117459. [PMID: 32092332 DOI: 10.1016/j.lfs.2020.117459] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 02/06/2023]
Abstract
Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus that affects approximately half of patients with diabetes. Current treatment regimens cannot treat DPN effectively. Schwann cells (SCs) are very sensitive to glucose concentration and insulin, and closely associated with the occurrence and development of type 1 diabetic mellitus (T1DM) and DPN. Apoptosis of SCs is induced by hyperglycemia and is involved in the pathogenesis of DPN. This review considers the pathological processes of SCs apoptosis under high glucose, which include the following: oxidative stress, inflammatory reactions, endoplasmic reticulum stress, autophagy, nitrification and signaling pathways (PI3K/AKT, ERK, PERK/Nrf2, and Wnt/β-catenin). The clarification of mechanisms underlying SCs apoptosis induced by high glucose will help us to understand and identify more effective strategies for the treatment of T1DM DPN.
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Affiliation(s)
- Yu-Pu Liu
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Shui-Jin Shao
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| | - Hai-Dong Guo
- Department of Anatomy, School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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30
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Uranbileg B, Ito N, Kurano M, Saigusa D, Saito R, Uruno A, Kano K, Ikeda H, Yamada Y, Sumitani M, Sekiguchi M, Aoki J, Yatomi Y. Alteration of the lysophosphatidic acid and its precursor lysophosphatidylcholine levels in spinal cord stenosis: A study using a rat cauda equina compression model. Sci Rep 2019; 9:16578. [PMID: 31719574 PMCID: PMC6851136 DOI: 10.1038/s41598-019-52999-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/22/2019] [Indexed: 12/13/2022] Open
Abstract
Cauda equina compression (CEC) is a major cause of neurogenic claudication and progresses to neuropathic pain (NP). A lipid mediator, lysophosphatidic acid (LPA), is known to induce NP via the LPA1 receptor. To know a possible mechanism of LPA production in neurogenic claudication, we determined the levels of LPA, lysophosphatidylcholine (LPC) and LPA-producing enzyme autotaxin (ATX), in the cerebrospinal fluid (CSF) and spinal cord (SC) using a CEC as a possible model of neurogenic claudication. Using silicon blocks within the lumbar epidural space, we developed a CEC model in rats with motor dysfunction. LPC and LPA levels in the CSF were significantly increased from day 1. Importantly, specific LPA species (16:0, 18:2, 20:4) were upregulated, which have been shown to produce by ATX detected in the CSF, without changes on its level. In SC, the LPC and LPA levels did not change, but mass spectrometry imaging analysis revealed that LPC was present in a region where the silicon blocks were inserted. These results propose a model for LPA production in SC and CSF upon neurogenic claudication that LPC produced locally by tissue damages is converted to LPA by ATX, which then leak out into the CSF.
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Affiliation(s)
- Baasanjav Uranbileg
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo, Japan
| | - Nobuko Ito
- Department of Anesthesiology and Pain Relief Center, The University of Tokyo, Tokyo, Japan.
| | - Makoto Kurano
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo, Japan
| | - Daisuke Saigusa
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Miyagi, Japan.,Medical Biochemistry, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Ritsumi Saito
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Miyagi, Japan.,Medical Biochemistry, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Akira Uruno
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Miyagi, Japan.,Medical Biochemistry, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Kuniyuki Kano
- Laboratory of Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan
| | - Hitoshi Ikeda
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshitsugu Yamada
- Department of Anesthesiology and Pain Relief Center, The University of Tokyo, Tokyo, Japan
| | - Masahiko Sumitani
- Department of Pain and Palliative Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Miho Sekiguchi
- Department of Orthopaedic Surgery, Fukushima Medical University, School of Medicine, Fukushima, Japan
| | - Junken Aoki
- Laboratory of Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo, Japan
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Ueda H. [Lysophosphatidic Acid Receptor Signaling Underlying Chronic Pain and Neuroprotective Mechanisms through Prothymosin α]. YAKUGAKU ZASSHI 2019; 139:1403-1415. [PMID: 31685737 DOI: 10.1248/yakushi.19-00160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
For my Ph.D. research topic, I isolated endogenous morphine-like analgesic dipeptide, kyotorphin, which mediates Met-enkephalin release, and discovered kyotorphin synthetase, a putative receptor and antagonist. Furthermore, I succeeded in purifying μ-opioid receptor and functional reconstitution with purified G proteins. After receiving my full professor position at Nagasaki University in 1996, I worked on two topics of research, molecular mechanisms of chronic pain through lysophosphatidic acid (LPA) and identification and characterization of neuroprotective protein, prothymosin α. In a series of studies, we have shown that LPA signaling defines the molecular mechanisms of neuropathic pain and fibromyalgia in terms of development and maintenance. Above all, the discovery of feed-forward system in LPA production and pain memory may contribute to better understanding of chronic pain and future analgesic drug discovery. Regarding prothymosin α, we first discovered it as neuronal necrosis-inhibitory molecule through two independent mechanisms, such as toll-like receptor and F0/F1 ATPase, both which protect neurons through indirect mechanisms. Prothymosin α is released by non-classical and non-vesicular mechanisms on various stresses, such as ischemia, starvation, and heat-shock. Thus it may be called a new type of neuroprotective damage-associated molecular patterns (DAMPs)/Alarmins. Heterozygotic mice showed a defect in memory-learning and neurogenesis as well as anxiogenic behaviors. Small peptide, P6Q derived from prothymosin α retains neuroprotective actions, which include blockade of cerebral hemorrhage caused by late treatment with tissue plasminogen activator in the stroke model in mice.
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Affiliation(s)
- Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University, Institute of Biomedical Sciences
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32
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Affiliation(s)
- Hiroshi Ueda
- Graduate School of Pharmaceutical Sciences, Kyoto University
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Prophylactic Repetitive Treatment with the Herbal Medicine Kei-kyoh-zoh-soh-oh-shin-bu-toh Attenuates Oxaliplatin-Induced Mechanical Allodynia by Decreasing Spinal Astrocytes. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:4029694. [PMID: 31118957 PMCID: PMC6500670 DOI: 10.1155/2019/4029694] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 03/24/2019] [Accepted: 04/09/2019] [Indexed: 01/27/2023]
Abstract
Chemotherapeutic drugs typically induce peripheral neuropathy, which is a major dose-limiting side effect of these drugs and is difficult to manage. In this study, we examined whether the traditional herbal formulation Kei-kyoh-zoh-soh-oh-shin-bu-toh (KSOT) could relieve the mechanical allodynia induced by chemotherapeutic drugs (oxaliplatin, paclitaxel, vincristine, and bortezomib) in mice. A single intraperitoneal injection of oxaliplatin, paclitaxel, vincristine, and bortezomib was used to induce mechanical allodynia, which peaked on days 10, 14, 14, and 12 after the injection, respectively. A single oral administration of KSOT did not inhibit mechanical allodynia after any of the treatments. However, prophylactic repetitive oral administrations of KSOT inhibited the exacerbation of mechanical allodynia induced by oxaliplatin but were not effective for allodynia induced by the other drugs. A single intraperitoneal injection of oxaliplatin did not alter the mRNA expression of the NMDA receptor NR2B in the spinal cord and that of neuregulin-1 in the sciatic nerve. In addition, the number of microglia in spinal dorsal horn did not increase in oxaliplatin-treated mice. However, the number of reactivated astrocytes in the spinal dorsal horn increased, which could be inhibited by repetitive administration of KSOT. These results suggest that prophylactic repetitive treatment of KSOT attenuates oxaliplatin-induced mechanical allodynia by decreasing the number of spinal astrocytes.
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Involvement of lysophosphatidic acid-induced astrocyte activation underlying the maintenance of partial sciatic nerve injury-induced neuropathic pain. Pain 2019; 159:2170-2178. [PMID: 29939962 DOI: 10.1097/j.pain.0000000000001316] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We have previously demonstrated that lysophosphatidic acid (LPA) plays key roles in the initial mechanisms for neuropathic pain (NeuP) development. Here, we examined whether LPA receptor mechanisms and LPA production are related to the glial activation at a late stage after partial sciatic nerve ligation (pSNL) by use of microglial inhibitor, Mac1-saporin or astrocyte inhibitor, and L-α-aminoadipate (L-AA). Although single intrathecal injection of LPA1/3 antagonist, Ki-16425 did not affect the pain threshold at day 7 after the spinal cord injury, repeated treatments of each compound gradually reversed the basal pain threshold to the control level. The intrathecal administration of a microglia inhibitor, Mac-1-saporin reversed the late hyperalgesia and LPA production at day 14 after the pSNL, whereas L-AA inhibited the hyperalgesia, but had no effect on LPA production. The involvement of LPA receptors in astrocyte activation in vivo was evidenced by the findings that Ki-16425 treatments abolished the upregulation of CXCL1 in activated astrocytes in the spinal dorsal horn of mice at day 14 after the pSNL, and that Ki-16425 reversed the LPA-induced upregulation of several chemokine gene expressions in primary cultured astrocytes. Finally, we found that significant hyperalgesia was observed with intrathecal administration of primary cultured astrocytes, which had been stimulated by LPA in a Ki-16425-reversible manner. All these findings suggest that LPA production and LPA1/3 receptor activation through differential glial mechanisms play key roles in the maintenance as well as initiation mechanisms in NeuP.
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35
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Ueda H, Neyama H, Sasaki K, Miyama C, Iwamoto R. Lysophosphatidic acid LPA 1 and LPA 3 receptors play roles in the maintenance of late tissue plasminogen activator-induced central poststroke pain in mice. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2019; 5:100020. [PMID: 31194070 PMCID: PMC6550111 DOI: 10.1016/j.ynpai.2018.07.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/17/2018] [Accepted: 07/19/2018] [Indexed: 11/17/2022]
Abstract
We developed a mouse model for central post-stroke pain (CPSP), a centrally-originated neuropathic pain (NeuP). In this mode, mice were first injected with Rose Bengal, followed by photo-irradiation of left middle cerebral artery (MCA) to generate thrombosis. Although the MCA thrombosis was soon dissolved, the reduced blood flow remained for more than 24 h due to subsequent occlusion of microvessels. This photochemically induced thrombosis (PIT) model showed a hypersensitivity to the electrical stimulation of both sides of paw, but did not show any abnormal pain in popular thermal or mechanical nociception tests. When tissue-type plasminogen activator (tPA) was injected 6 h after the PIT stress, tPA-dependent hypersensitivity to the electrical paw stimulation and stable thermal and mechanical hyperalgesia on both sides for more than 17 or 18 days after the PIT treatment. These hyperalgesic effects were abolished in lysophosphatidic acid receptor 1 (LPA1)- and lysophosphatidic acid receptor 3 (LPA3)-deficient mice. When Ki-16425, an LPA1 and LPA3 antagonist was treated twice daily for 6 days consecutively, the thermal and mechanical hyperalgesia at day 17 and 18 were significantly reversed. The liquid chromatography-mass spectrometry (LC-MS/MS) analysis revealed that there is a significant increase in several species of LPA molecules in somatosensory S-I and medial dorsal thalamus (MD), but not in striatum or ventroposterior thalamus. All these results suggest that LPA1 and LPA3 signaling play key roles in the development and maintenance of CPSP.
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Key Words
- CPSP, central post-stroke pain
- Central poststroke pain
- DMSO, dimethyl sulfoxide
- EPW, electrical stimulation-induced paw withdrawal
- HE, Hematoxylin and Eosin
- LC–MS/MS
- LC–MS/MS, liquid chromatography–mass spectrometry
- LPA1, lysophosphatidic acid receptor 1
- LPA1-KO, LPA1-deficient
- LPA3, lysophosphatidic acid receptor 3
- Lysophosphatidic acid
- MCA, middle cerebral artery
- MD, medial dorsal thalamus
- MRM, multiple reaction monitoring
- NeuP, neuropathic pain
- PFA, paraformaldehyde
- PIT, photochemically induced thrombosis
- PWL, paw withdrawal latency
- Photochemically induced thrombosis
- RB, Rose Bengal
- S-I, sensory cortex
- TTC, 2,3,5-triphenyltetrazolium chloride
- i.v., intravenously
- pSNL, partial sciatic nerve ligation
- tMCAO, transient middle cerebral artery occlusion
- tPA
- tPA, tissue-type plasminogen activator
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Affiliation(s)
- Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University, Institute of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
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Wu S, Bono J, Tao YX. Long noncoding RNA (lncRNA): a target in neuropathic pain. Expert Opin Ther Targets 2018; 23:15-20. [PMID: 30451044 DOI: 10.1080/14728222.2019.1550075] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Current treatments for neuropathic pain are limited in part due to the incomplete understanding of its underlying mechanisms. Recent evidence reveals the dysregulated expression of long non-coding RNAs (lncRNAs) in the damaged nerve, dorsal root ganglion (DRG), and spinal cord dorsal horn following peripheral nerve injury. However, the role of the majority of lncRNAs in neuropathic pain genesis is still elusive. Unveiling the mechanisms of how lncRNAs participate in neuropathic pain may develop new strategies to prevent and/or treat this disorder. Areas covered: This review focuses on the dysregulation of lncRNAs in the DRG, dorsal horn, and the injured nerves from preclinical models of neuropathic pain. We provide evidence of how peripheral nerve injury causes the dysregulation of lncRNAs in these pain-related regions. The potential mechanisms of how dysregulated lncRNAs contribute to the pathogenesis of neuropathic pain are discussed. Expert opinion: The investigation on the role of the dysregulated lncRNAs in neuropathic pain might open up a novel avenue for therapeutic treatment of this disorder. However, current investigation is at the infancy stage, which challenges the translation of preclinical findings. More intensive studies on lncRNAs are required before the preclinical findings are translated into therapeutic management for neuropathic pain.
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Affiliation(s)
- Shaogen Wu
- a Department of Anesthesiology , New Jersey Medical School, Rutgers, The State University of New Jersey , Newark , NJ , USA
| | - Jamie Bono
- a Department of Anesthesiology , New Jersey Medical School, Rutgers, The State University of New Jersey , Newark , NJ , USA
| | - Yuan-Xiang Tao
- a Department of Anesthesiology , New Jersey Medical School, Rutgers, The State University of New Jersey , Newark , NJ , USA
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Kuwajima K, Sumitani M, Kurano M, Kano K, Nishikawa M, Uranbileg B, Tsuchida R, Ogata T, Aoki J, Yatomi Y, Yamada Y. Lysophosphatidic acid is associated with neuropathic pain intensity in humans: An exploratory study. PLoS One 2018; 13:e0207310. [PMID: 30408112 PMCID: PMC6224112 DOI: 10.1371/journal.pone.0207310] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/29/2018] [Indexed: 12/15/2022] Open
Abstract
The underlying mechanisms of neuropathic pain remain to be elucidated. Basic animal research has suggested that lysophosphatidic acids, which are bioactive lipids produced by autotaxin from lysophosphatidylcholine, may play key roles in the initiation and maintenance of neuropathic pain. Here, we investigated the clinical relevance of lysophosphatidic acids signaling on neuropathic pain in humans. Eighteen patients who had been diagnosed with neuropathic pain with varied etiologies participated in the study. Cerebrospinal fluid samples were obtained by lumbar puncture and the concentrations of 12 species of lysophosphatidic acids and lysophosphatidylcholine, autotaxin, and the phosphorylated neurofilament heavy subunit were measured. Pain symptoms were assessed using an 11-point numeric rating scale and the Neuropathic Pain Symptom Inventory regarding intensity and descriptive dimensions of neuropathic pain. The total lysophosphatidic acids were significantly associated with both pain intensity and symptoms. 18:1 and 20:4 lysophosphatidic acids in particular demonstrated the most correlations with dimensions of pain symptoms. Autotaxin and the phosphorylated neurofilament heavy subunit showed no association with pain symptoms. In conclusions, lysophosphatidic acids were significantly associated with pain symptoms in neuropathic pain patients. These results suggest that lysophosphatidic acids signaling might be a potential therapeutic target for neuropathic pain.
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Affiliation(s)
- Ken Kuwajima
- Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Masahiko Sumitani
- Department of Pain and Palliative Medicine, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
- * E-mail:
| | - Makoto Kurano
- Department of Clinical Laboratory Medicine, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Kuniyuki Kano
- Department of Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Masako Nishikawa
- Department of Clinical Laboratory Medicine, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Baasanjav Uranbileg
- Department of Clinical Laboratory Medicine, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Rikuhei Tsuchida
- Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Toru Ogata
- Department of Rehabilitation for Movement Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Saitama, Japan
| | - Junken Aoki
- Department of Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory Medicine, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
| | - Yoshitsugu Yamada
- Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan
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Singh H, Bhushan S, Arora R, Singh Buttar H, Arora S, Singh B. Alternative treatment strategies for neuropathic pain: Role of Indian medicinal plants and compounds of plant origin-A review. Biomed Pharmacother 2017; 92:634-650. [DOI: 10.1016/j.biopha.2017.05.079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 01/28/2023] Open
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Andoh T, Uta D, Kato M, Toume K, Komatsu K, Kuraishi Y. Prophylactic Administration of Aucubin Inhibits Paclitaxel-Induced Mechanical Allodynia via the Inhibition of Endoplasmic Reticulum Stress in Peripheral Schwann Cells. Biol Pharm Bull 2017; 40:473-478. [PMID: 28381802 DOI: 10.1248/bpb.b16-00899] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Paclitaxel is a chemotherapeutic agent that causes peripheral neuropathy as its major dose-limiting side effect. However, the peripheral neuropathy is difficult to manage. A study we recently conducted showed that repetitive administration of aucubin as a prophylactic inhibits paclitaxel-induced mechanical allodynia. However, the mechanisms underlying the anti-allodynic activity of aucubin, which is a major component of Plantaginis Semen, was unclear. In addition to mechanical allodynia, aucubin inhibited spontaneous and mechanical stimuli-induced firing in spinal dorsal horn neurons; however, catalpol, a metabolite of aucubin, did not show these effects. Furthermore, paclitaxel induced the expression of CCAAT/enhancer-binding protein homologous protein, a marker of endoplasmic reticulum (ER) stress, in the sciatic nerve and a Schwann cell line (LY-PPB6 cells); however, this effect was inhibited by aucubin. These results suggest that aucubin inhibits paclitaxel-induced mechanical allodynia through the inhibition of ER stress in peripheral Schwann cells.
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Affiliation(s)
- Tsugunobu Andoh
- Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
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Ueda H, Neyama H. LPA1 receptor involvement in fibromyalgia-like pain induced by intermittent psychological stress, empathy. NEUROBIOLOGY OF PAIN 2017; 1:16-25. [PMID: 31194005 PMCID: PMC6550118 DOI: 10.1016/j.ynpai.2017.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 04/07/2017] [Accepted: 04/10/2017] [Indexed: 12/22/2022]
Abstract
Treatment for fibromyalgia is an unmet medical need and its pathogenesis is still poorly understood. The present study demonstrated that intermittent psychological stress (IPS), or empathy causes generalized chronic abnormal pain with female predominance. The persistence of the pain phenotype was dependent on the unpredictability of the stressor. The pain was reversed by pregabalin (PGB), duloxetine (DLX) or mirtazapine (Mir), but not by diclofenac or morphine. Differential administration of these existing medicines revealed that the sites of PGB and Mir actions exist in the brain, but not in the spinal cord, while that of DLX is preferentially in the spinal cord. It is interesting to note that the intracerebroventricular injection of PGB or Mir showed potent analgesia for 24 h or longer, though systemic injection of these medicines shows anti-hyperalgesia just for several hours. These results indicate that initial intense actions in the target brain may prevent the forthcoming development of pain memory. IPS-induced abnormal pain was prevented in mice deficient of lysophosphatidic acid receptor 1 (LPA1) gene, and completely cured by the repeated intrathecal treatments with LPA1 antagonist, AM966, which did not show acute action. All these results suggest that IPS model is an experimental animal model, which mimics the pathophysiology and pharmacotherapy in fibromyalgia in clinic, and LPA1 signaling plays crucial roles in the IPS-induced fibromyalgia-like abnormal pain.
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Affiliation(s)
- Hiroshi Ueda
- Corresponding author at: Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
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Wang IC, Chung CY, Liao F, Chen CC, Lee CH. Peripheral sensory neuron injury contributes to neuropathic pain in experimental autoimmune encephalomyelitis. Sci Rep 2017; 7:42304. [PMID: 28181561 PMCID: PMC5299449 DOI: 10.1038/srep42304] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/05/2017] [Indexed: 11/09/2022] Open
Abstract
Multiple sclerosis (MS)-induced neuropathic pain deteriorates quality of life in patients but is often refractory to treatment. In experimental autoimmune encephalomyelitis (EAE), a rodent model of MS, animals develop neuropathy and inflammation-induced tissue acidosis, which suggests the involvement of acid-sensing ion channels (ASICs). Also, peripheral neuropathy is reported in MS patients. However, the involvement of the peripheral nervous system (PNS) in MS neuropathic pain remains elusive. This study investigated the contribution of ASICs and peripheral neuropathy in MS-induced neuropathic pain. Elicited pain levels were as high in Asic1a-/-, Asic2-/- and Asic3-/- mice as wild-type mice even though only Asic1a-/- mice showed reduced EAE disease severity, which indicates that pain in EAE was independent of disease severity. We thus adopted an EAE model without pertussis toxin (EAEnp) to restrain activated immunity in the periphery and evaluate the PNS contribution to pain. Both EAE and EAEnp mice showed similar pain behaviors and peripheral neuropathy in nerve fibers and DRG neurons. Moreover, pregabalin significantly reduced neuropathic pain in both EAE and EAEnp mice. Our findings highlight the essential role of the PNS in neuropathic pain in EAE and pave the way for future development of analgesics without side effects in the CNS.
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Affiliation(s)
- I-Ching Wang
- Institute of Biomedical Sciences, Academia Sinica, 128, Sec. 2, Academia Rd., Taiwan.,Department of Life Science, National Taiwan University, Taiwan
| | - Chen-Yen Chung
- Institute of Biomedical Sciences, Academia Sinica, 128, Sec. 2, Academia Rd., Taiwan
| | - Fang Liao
- Institute of Biomedical Sciences, Academia Sinica, 128, Sec. 2, Academia Rd., Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, 128, Sec. 2, Academia Rd., Taiwan.,Department of Life Science, National Taiwan University, Taiwan
| | - Cheng-Han Lee
- Institute of Biomedical Sciences, Academia Sinica, 128, Sec. 2, Academia Rd., Taiwan
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Lysophosphatidic acid signaling is the definitive mechanism underlying neuropathic pain. Pain 2017; 158 Suppl 1:S55-S65. [DOI: 10.1097/j.pain.0000000000000813] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Hannaman MR, Fitts DA, Doss RM, Weinstein DE, Bryant JL. The refined biomimetic NeuroDigm GEL™ model of neuropathic pain in a mature rat. F1000Res 2016. [PMID: 28620451 PMCID: PMC5461904 DOI: 10.12688/f1000research.9544.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background: Many humans suffering with chronic neuropathic pain have no objective evidence of an etiological lesion or disease. Frequently their persistent pain occurs after the healing of a soft tissue injury. Based on clinical observations over time, our hypothesis was that after an injury in mammals the process of tissue repair could cause chronic neural pain. Our objectives were to create the delayed onset of neuropathic pain in rats with minimal nerve trauma using a physiologic hydrogel, and characterize the rats' responses to known analgesics and a targeted biologic. Methods: In mature male Sprague Dawley rats (age 9.5 months) a percutaneous implant of tissue-derived hydrogel was placed in the musculofascial tunnel of the distal tibial nerve. Subcutaneous morphine (3 mg/kg), celecoxib (10 mg/kg), gabapentin (25 mg/kg) and duloxetine (10 mg/kg) were each screened in the model three times each over 5 months after pain behaviors developed. Sham and control groups were used in all screenings. A pilot study followed in which recombinant human erythropoietin (200 units) was injected by the GEL™ neural procedure site. Results: The GEL group gradually developed mechanical hypersensitivity lasting months. Morphine, initially effective, had less analgesia over time. Celecoxib produced no analgesia, while gabapentin and duloxetine at low doses demonstrated profound analgesia at all times tested. The injected erythropoietin markedly decreased bilateral pain behavior that had been present for over 4 months, p ≤ 0.001. Histology of the GEL group tibial nerve revealed a site of focal neural remodeling, with neural regeneration, as found in nerve biopsies of patients with neuropathic pain. Conclusion: The refined NeuroDigm GEL™ model induces a neural response resulting in robust neuropathic pain behavior. The analgesic responses in this model reflect known responses of humans with neuropathic pain. The targeted recombinant human erythropoietin at the ectopic neural lesion appears to alleviate the persistent pain behavior in the GEL™ model rodents.
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Affiliation(s)
- Mary R Hannaman
- NeuroDigm Corporation, Colorado Springs, CO, 80906, USA.,Department of Integrative Physiology, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA
| | - Douglas A Fitts
- Office of Animal Welfare, University of Washington, Seattle, WA, 98195, USA
| | - Rose M Doss
- Department of Biology, University of Colorado, Colorado Springs, CO, 80918, USA
| | | | - Joseph L Bryant
- Animal Model Division, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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Hannaman MR, Fitts DA, Doss RM, Weinstein DE, Bryant JL. The refined biomimetic NeuroDigm GEL™ Model of neuropathic pain in the mature rat. F1000Res 2016; 5:2516. [DOI: 10.12688/f1000research.9544.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/04/2016] [Indexed: 01/10/2023] Open
Abstract
Background:Many humans suffering with chronic pain have no clinical evidence of a lesion or disease. They are managed with a morass of drugs and invasive procedures. Opiates usually become less effective over time. In many, their persistent pain occurs after the healing of a soft tissue injury. Current animal models of neuropathic pain typically create direct neural damage with open surgeries using ligatures, neurectomies, chemicals or other forms of deliberate trauma. However, we have observed clinically that after an injury in humans, the naturally occurring process of tissue repair can cause chronic neural pain.Methods:We demonstrate how the refined biomimetic NeuroDigm GEL™ Model, in the mature male rat, gradually induces neuropathic pain behavior with a nonsurgical percutaneous implant of tissue-derived hydrogel in the musculo-fascial tunnel of the distal tibial nerve. Morphine, Celecoxib, Gabapentin and Duloxetine were each screened in the model three times each over 5 months after pain behaviors developed. A pilot study followed in which recombinant human erythropoietin was applied to the GEL neural procedure site.Results:The GEL Model gradually developed neuropathic pain behavior lasting months. Morphine, initially effective, had less analgesia over time. Celecoxib produced no analgesia, while gabapentin and duloxetine at low doses had profound analgesia at all times tested. The injected erythropoietin markedly decreased bilateral pain behavior that had been present for over 4 months. Histology revealed a site of focal neural remodeling, with neural regeneration, as in human biopsies.Conclusion:The refined NeuroDigm GEL™ Model induces localized neural remodeling resulting in robust neuropathic pain behavior. The analgesics responses in this model reflect known responses of humans with neuropathic pain. The targeted recombinant human erythropoietin appears to heal the ectopic focal neural site, as demonstrated by the extinguishing of neuropathic pain behavior present for over 4 months.
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Wu JX, Yuan XM, Wang Q, Wei W, Xu MY. Rho/ROCK acts downstream of lysophosphatidic acid receptor 1 in modulating P2X3 receptor-mediated bone cancer pain in rats. Mol Pain 2016; 12:12/0/1744806916644929. [PMID: 27094551 PMCID: PMC4956381 DOI: 10.1177/1744806916644929] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 03/20/2016] [Indexed: 12/27/2022] Open
Abstract
Background Lysophosphatidic acid receptor 1 and Rho/ROCK signaling is implicated in bone cancer pain development. However, it remains unknown whether the two signaling pathways function together in P2X3 receptor-mediated bone cancer pain. Results In this study, using a rat model of bone cancer, we examined the expression of P2X3 and lysophosphatidic acid receptor 1 in rat dorsal root ganglion neurons and further dissected whether lysophosphatidic acid receptor 1 and Rho/ROCK-mediated pathways interacted in modulating rat pain behavior. Bone cancer was established by inoculating Walker 256 cells into the left tibia of female Wistar rats. We observed a gradual and yet significant decline in mean paw withdrawal threshold in rats with bone cancer, but not in control rats. Our immunohistochemical staining revealed that the number of P2X3- and lysophosphatidic acid receptor 1-positive dorsal root ganglion neurons was significantly greater in rats with bone cancer than control rats. Lysophosphatidic acid receptor 1 blockade with VPC32183 significantly attenuated decline in mean paw withdrawal threshold. Flinching behavior test further showed that lysophosphatidic acid receptor 1 inhibition with VPC32183 transiently but significantly attenuated α,β-meATP-induced increase in paw lift time per minute. Rho inhibition by intrathecal BoTXC3 caused a rapid reversal in decline in mean paw withdrawal threshold of rats with bone cancer. Flinching behavior test showed that BoTXC3 transiently and significantly attenuated α,β-meATP-induced increase in paw lift time per minute. Similar findings were observed with ROCK inhibition by intrathecal Y27632. Furthermore, VPC32183 and BoTXC3 effectively aborted the appearance of lysophosphatidic acid-induced calcium influx peak. Conclusions Lysophosphatidic acid and its receptor LPAR1, acting through the Rho-ROCK pathway, regulate P2X3 receptor in the development of both mechanical and spontaneous pain in bone cancer.
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Affiliation(s)
- Jing-Xiang Wu
- Department of Anesthesiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China
| | - Xiao-Min Yuan
- Department of Anesthesiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China
| | - Qiong Wang
- Department of Anesthesiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China
| | - Wang Wei
- Department of Anesthesiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China
| | - Mei-Ying Xu
- Department of Anesthesiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, PR China
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Sasaki K, Omotuyi OI, Ueda M, Shinohara K, Ueda H. NMDA receptor agonists reverse impaired psychomotor and cognitive functions associated with hippocampal Hbegf-deficiency in mice. Mol Brain 2015; 8:83. [PMID: 26637193 PMCID: PMC4670538 DOI: 10.1186/s13041-015-0176-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Structural and functional changes of the hippocampus are correlated with psychiatric disorders and cognitive dysfunctions. Genetic deletion of heparin-binding epidermal growth factor-like growth factor (HB-EGF), which is predominantly expressed in cortex and hippocampus, also causes similar psychiatric and cognitive dysfunctions, accompanying down-regulated NMDA receptor signaling. However, little is known of such dysfunctions in hippocampus-specific Hbegf cKO mice. RESULTS We successfully developed hippocampus-specific cKO mice by crossbreeding floxed Hbegf and Gng7-Cre knock-in mice, as Gng7 promoter-driven Cre is highly expressed in hippocampal neurons as well as striatal medium spiny neurons. In mice lacking hippocampus Hbegf gene, there was a decreased neurogenesis in the subgranular zone (SGZ) of the dentate gyrus as well as down-regulation of PSD-95/NMDA-receptor-NR1/NR2B subunits and related NMDA receptor signaling. Psychiatric, social-behavioral and cognitive abnormalities were also observed in hippocampal cKO mice. Interestingly, D-cycloserine and nefiracetam, positive allosteric modulators (PAMs) of NMDA receptor reversed the apparent reduction in NMDA receptor signaling and most behavioral abnormalities. Furthermore, decreased SGZ neurogenesis in hippocampal cKO mice was reversed by nefiracetam. CONCLUSIONS The present study demonstrates that PAMs of NMDA receptor have pharmacotherapeutic potentials to reverse down-regulated NMDA receptor signaling, neuro-socio-cognitive abnormalities and decreased neurogenesis in hippocampal cKO mice.
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Affiliation(s)
- Keita Sasaki
- Department of Pharmacology and Therapeutic Innovation, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
| | - Olaposi Idowu Omotuyi
- Department of Pharmacology and Therapeutic Innovation, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
| | - Mutsumi Ueda
- Department of Pharmacology and Therapeutic Innovation, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
| | - Kazuyuki Shinohara
- Department of Neurobiology and Behavior, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, 852-8523, Japan.
| | - Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
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Kiyoyuki Y, Taniguchi W, Okubo M, Yamanaka H, Kobayashi K, Nishio N, Nakatsuka T, Noguchi K. Leukotriene enhances NMDA-induced inward currents in dorsal horn neurons of the rat spinal cord after peripheral nerve injury. Mol Pain 2015; 11:53. [PMID: 26353783 PMCID: PMC4563829 DOI: 10.1186/s12990-015-0059-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 08/31/2015] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND LTB4 is classified as a leukotriene (LT), a group of lipid mediators that are derived from arachidonic acid. It is recognized that leukotrienes are involved in the pathogenesis of many diseases, including peripheral inflammatory pain. However, little is known about the effects of leukotrienes on the spinal dorsal horn during neuropathic pain. Previously, we reported that there was increased expression of 5-lipoxygenase (5-LO) at spinal microglia, and the leukotriene B4 receptor 1 (BLT1), a high affinity receptor of LTB4, in spinal neurons in spared nerve injury (SNI) model rats. In the present study, we examined the effects of LTB4 on spinal dorsal horn neurons in both naïve and SNI model rats using patch-clamp methods. RESULTS Bath application of LTB4 did not change AMPA receptor-mediated spontaneous excitatory postsynaptic currents (sEPSCs) or membrane potentials. However, we found that LTB4 enhanced the amplitude of NMDA receptor-mediated sEPSCs and significantly increased exogenous NMDA-induced inward currents in SNI model rats. This increase of inward currents could be inhibited by a selective LTB4 antagonist, U75302, as well as a GDP-β-S, a G-protein inhibitor. These results indicate that both increased LTB4 from spinal microglia or increased BLT1 in spinal neurons after peripheral nerve injury can enhance the activity of NMDA receptors through intracellular G-proteins in spinal dorsal horn neurons. CONCLUSION Our findings showed that LTB4, which may originate from microglia, can activate BLT1 receptors which are expressed on the membrane of spinal dorsal horn neurons during neuropathic pain. This glia-neuron interaction induces the enhancement of NMDA currents through intracellular G-proteins. The enhancement of NMDA receptor sensitivity of dorsal horn neurons may lead to central sensitization, leading to mechanical pain hypersensitivity.
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Affiliation(s)
- Yasukuni Kiyoyuki
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan. .,Pain Research Center, Kansai University of Health Sciences, 2-11-1 Wakaba Kumatori-cho, Osaka, 590-0482, Japan.
| | - Wataru Taniguchi
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Mimiidera, Wakayama, 641-8510, Japan.
| | - Masamichi Okubo
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
| | - Hiroki Yamanaka
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
| | - Kimiko Kobayashi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
| | - Naoko Nishio
- Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Mimiidera, Wakayama, 641-8510, Japan.
| | - Terumasa Nakatsuka
- Pain Research Center, Kansai University of Health Sciences, 2-11-1 Wakaba Kumatori-cho, Osaka, 590-0482, Japan.
| | - Koichi Noguchi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
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Hirose M, Kuroda Y, Murata E. NGF/TrkA Signaling as a Therapeutic Target for Pain. Pain Pract 2015; 16:175-82. [PMID: 26452158 DOI: 10.1111/papr.12342] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 06/15/2015] [Indexed: 01/03/2023]
Abstract
Nerve growth factor (NGF) was first discovered approximately 60 years ago by Rita Levi-Montalcini as a protein that induces the growth of nerves. It is now known that NGF is also associated with Alzheimer's disease and intractable pain, and hence, it, along with its high-affinity receptor, tropomyosin receptor kinase (Trk) A, is considered to be 1 of the new targets for therapies being developed to treat these diseases. Anti-NGF antibody and TrkA inhibitors are known drugs that suppress NGF/TrkA signaling, and many drugs of these classes have been developed thus far. Interestingly, local anesthetics also possess TrkA inhibitory effects. This manuscript describes the development of an analgesic that suppresses NGF/TrkA signaling, which is anticipated to be 1 of the new methods to treat intractable pain.
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Affiliation(s)
- Munetaka Hirose
- Department of Anesthesiology and Pain Medicine, Hyogo College of Medicine, Hyogo, Japan
| | - Yoshihiro Kuroda
- Department of Pharmaceutical Health Care, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Hyogo, Japan
| | - Eri Murata
- Department of Anesthesiology and Reanimatology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
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Mukae T, Uchida H, Ueda H. Donepezil Reverses Intermittent Stress-Induced Generalized Chronic Pain Syndrome in Mice. J Pharmacol Exp Ther 2015; 353:471-9. [DOI: 10.1124/jpet.114.222414] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 03/23/2015] [Indexed: 01/27/2023] Open
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